What to do:1 Put the beans in a bowl, cover with cold water and leave to soak overnight.

2 Drain the beans and put in a flameproof casserole. Cover with water and bring to the boil. Reduce the heat and simmer gently for 15-20 minutes or until the beans have softened slightly. Test by removing a few on a fork and squeezing them gently – they should give a little. Drain the beans.

3 Wipe out the dish and melt the butter. Add the bacon and pork and fry gently for 10 minutes until beginning to brown. Add the onion and cook for a further 5 minutes.

4 Stir in the drained beans, thyme or rosemary and tomatoes. Add enough water to just cover the ingredients and bring to the boil. Cover with a lid and transfer to a preheated oven, 150ºC (300ºF), Gas Mark 2. Cook for about 1 hour or until the beans are very tender.

5 Mix together the treacle, tomato purée, mustard, Worcestershire sauce and seasoning. Stir into the beans and return to the oven for a further 30 minutes.